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Overseas information: www.cdc.gov/ncidod/diseases/Index.htm

TYPHOID FEVER

The Disease: - This disease is characterised by high fever (onset 5-21 days), abdominal pain with or without diarrhoea, enlarged spleen (3dr week) and rose coloured spots confined to chest & abdomen. It can infect the blood (septicaemia) which has a fatality rate of 10 - 20 % if untreated & 1% in treated persons. The risk of infection is generally low, approximately 1 in 30,000 for travellers to developing countries spending 4 weeks. Risk is 10 times higher in parts of India, Africa & South America. Typhoid is generally a milder illness in children under 5.  Risk is increased by failing to observe hygiene ... cook it, peel it or forget it !

Vaccine recommendation: - For anyone travelling to developing countries where the food and water quality is uncertain and persons with impaired gastric acid or immune deficiency. Most travel clinics do not recommend vaccine for travellers spending less than 2 weeks in popular tourist resorts. However, you can request to be vaccinated & the vaccine is well tolerated, (but expensive).

Vaccination:  .. CDC Vaccine information statement .. copy  (see also CMI pdf)

• Capsules:  "CSL-Vivotif(R) Oral", on alternate days, 1 hour before food for 3-4 doses. A 4th dose on day 7 has been estimated to increase immunity by an extra 40%. Boosters every 3-5 years depending on regime. Clinical disease is uncommon in children under 2 years of age. Vaccine can be given in children over the age of  6 years.  Some medicines and "Vivotif(R) Oral", may interfere with each other. These include: sulphonamides, antibiotics & antimalarials. [ Nb. mefloquine, chloraquine and malarone do not interfere with IgG O immune response BUT it is still recommended that they should be taken at least 1 week after the (final) dose of "Vivotif(R) Oral" (WHO recommends 10 days) ]. Oral typhoid capsules should be stored in the refrigerator (not freezer - as this will inactivate vaccine) until taken. Contrary to NHMRC guidelines, it is argued that other live vaccines, Sabin, MMR, yellow fever and oral cholera vaccine can be given at the same time as oral typhoid. Oral cholera vaccine is actually enhanced by giving it with oral typhoid. ref: page 123 Manual Travel Medicine

• Injection  - Typhim Vi  polysaccharide vaccine (CSL) & Typherix (SKB) is estimated to be as effective as the 4 dose oral typhoid provided the oral typhoid capsules are given with adherence to the above recommendations (approx 70 - 80% effective). A single injection is simple, immune response quicker and can be used in children over 2 years. - booster every 3 years.  

Typhoid Fever (enteric fever)
A bacterial infection characterised by diarrhoea, systemic disease, and a rash; most commonly caused by Salmonella typhi.
Typhi are spread by contaminated food, drink, or water. Following ingestion, the bacteria spread from the intestine to the intestinal lymph nodes, liver, and spleen via the blood where they multiply. Salmonella may directly infect the gallbladder through the hepatic duct or spread to other areas of the body through the bloodstream.
Early symptoms are very general and include fever, malaise and abdominal pain. As the disease progresses the fever becomes higher and diarrhoea becomes prominent and may be bloody. Weakness, profound fatigue, delirium, blood noses, obtundation(swollen abdomen) develop. A rash, characteristic only of typhoid and called "rose spots," appears in most cases of typhoid. Rose spots are small (1/4 inch) dark red, flat spots that appear most often on the abdomen and chest. Typically, children have milder disease and fewer complications than adults. A few people can become carriers of typhoid and continue to shed the bacteria in their faeces for years.

PREVENTION
Immunisation is not always completely effective and at-risk travellers should drink only boiled or bottled water and eat well cooked food.
SIGNS AND TESTS
A blood culture during first week of the fever can show Salmonella typhi bacteria. Note: A stool culture is unreliable.
Other tests:
- platelet count (decreased platelets)
- fluorescent antibody study (demonstrates Vi antigen, which is specific for typhoid)
TREATMENT
Intravenous fluids and electrolytes are usually given. Appropriate antibiotics are given to fight the bacteria; (preferred is ceftriaxone - ciprofloxacin, chloramphenicol resistance common).
The illness usually resolves in 2 to 4 weeks with treatment. The outcome is likely to be good with early treatment, but becomes poor if complications develop. Cases in children are milder, and are more debilitating in the elderly. Relapse may occur if the treatment has not fully eradicated the infection.